When I first started becoming more observant, I started fasting תענית בכורות/Fast of the Firstborn on erev Pesach. After I became fully observant, I learned that I had been wrong to fast on two counts: I am no longer a בכור so I didn't have to fast. The custom is for בכורים to attend a siyum in order to participate in a s'udas mitzvah and not to fast. Live and learn. The truth is that תענית בכורות is a strange fast anyway. It's the only fast where the minhag is to not fast. That is, attendance of a siyum is not seen as a "if you happen to attend a siyum you don't have to fast", instead it is the observance of choice. Groups plan ahead to have a siyum scheduled with the express purpose of getting the בכורים off the hook. I have seen two explanations of this phenomenon. R' Shlomo Zalman Auerbach, ztz"l, explains that that the בכורים are fasting because originally it was the בכור in each family who was responsible for the avodah. The...
This is a paraphrase of the pasuk in t'hillim 84:7 -- "mei'chayil el chayil" -- which means "from strength to strength". In this case, it is my thoughts and ideas to those who are strong enough to be interested :)